Hialeah police spokesman Carl Zogby says it is believed to be an accident.

A Hialeah fire spokesman says a maid at Presidente Motel called 911 Monday after looking through a window and seeing several of the teens unconscious.

Police say they had rented the room Sunday to celebrate one of teens' 19th birthday. A car that had needed a jump-start earlier was left running in the garage. A door leading to a staircase up to the room had been left open, and high levels of carbon monoxide were found inside.

Officials say no alcohol, illegal drugs or other suspicious items were found inside the room.